This invention relates to coin and key operated cam locks wherein a person places a coin into the lock and turns the key from its open to its locked position afterwhich the key may be removed. Such cam locks are typically used in lockable snow ski and pole racks, bicycle racks, rentable lockers and the like.
Coin and key operated cam locks are typically mounted on the inside of a wall or housing so that access to their working parts may not be had from the outside. From the outside one may view a coin receiving opening, perhaps part of the securing means or mechanism and a key which typically is only removable when the cam lock is in its fully locked position.
From the inside of the housing or wall, the working parts of the cam lock may be seen and generally include a cam disc mounted for rotation onto the mounting plate, wall or housing. A lock barrel is disposed within the disc so that the cam disc can be rotated by the key inserted into the lock barrel. A coin receiving slot is located within the cam disc alignable with the coin receiving opening in the plate or wall. A cam lever is suitably mounted on the plate or wall for pivotal movement about an axis parallel to the axis of rotation of the cam disc. The lever has a detent lug thereon which is adapted to engage a ramp of the cam disc to thereby releasably restrict rotation on the cam disc. The lever appropriately has a coin engaging surface engageable by a coin placed in the coin receiving slot through the coin receiving opening to force the detent lug out of engagement with the disc ramp to permit rotation of the cam disc towards its locked position.
Once the cam disc has reached its locked position, the coins fall out of the coin receiving slot into a separate coin receiving container. The key may then be removed from the key barrel for safe keeping until the user or key holder wishes to unlock the cam lock.
To prevent multiple uses of a single coin, the cam disc ramp has shoulder stops engageable with the detent lug which prevent the cam disc from moving from its fully locked position in a rotating manner towards the unlocked position and then back to the locked position again for key removal. Because the key can be removed from the key barrel only when the cam disc is fully and completely rotated to the locked position, a problem arises should there be any rotation of the cam disc from the locked position engaging a shoulder stop before the operator removes the key.
Consequently, users have experienced the loss of their coins without securing the properly rented key from of the cam lock. This often occurs when the user reaches the fully locked position of the cam lock and then wiggles the key to the point where the cam lever lug reaches a stop shoulder and will not permit the operator to again advance the cam disc to its fully locked position to enable him to remove the properly rented key.
This problem involves great service expense in that the cam locks must be inspected for proper operation and refunds must be distributed.